A carburettor is a device used in petrol internal combustion engines (ICE) that controls the air and fuel mixture entering the engine. It was Karl Benz who patented the first carburettor in 1885 and laid the groundwork for future improvements in the technology.
What is a carburettor?
The term carburettor is derived from the verb “carburet”, which basically means to combine carbons or hydrocarbons for enriching a gas/petrol in order to make it ideal for combustion.
Understanding how a carburettor actually works is important not just for your motorcycle's performance but is also essential for its proper maintenance.
How Does a Carburettor Work?
Initially, when air from the air filter enters the motorcycle carburettor, it has fuel added to it. Subsequently, it enters through the cylinder head via the inlet manifold. A very renowned principle of fluid dynamics known as “Bernoulli principle” works for a carburettor. The static pressure of the intake air reduces at a higher speed, ultimately drawing more fuel into the air stream.
This low pressure draws fuel from a reservoir into the airstream, creating a combustible mixture. The ratio of fuel to air can be adjusted using various components within the carburettor, such as the choke, throttle valve, and jet needles.
Getting the air-fuel mixture just right is the carburettor’s job.
Main Components of a Carburettor
• Main Nozzle: It has a very crucial role in the functioning - it is the main transmitter of the fuel as it gets fuel supply via float chamber, which directs fuel to the main fuel jet.
• Floater: It is another very crucial component in a carburettor. It helps the float chamber maintain an ideal pressure and it primarily works in high or low fuel conditions. The floater ensures stable running condition.
• Floater chamber: Its key purpose is to supply fuel to the main nozzle through the fuel jet. It maintains constant pressure by controlling the flow rate as per the demand.
• Throttle Valve: Also known as a piston valve, it functions as a regulator of air and fuel mixture entering the combustion chamber. The throttle valve and main jet work in sync; when the throttle valve is open, the main jet is open as well. The throttle valve needs regular maintenance to ensure a stable condition for your vehicle.
• Choke valve: It modifies the air pressure in the intake manifold and alters the air-fuel ratio. The choke valve kills the reservoir pressure and regulates the downstream flow line pressure. It consists of a plug that moves up and down inside the slotted cylinder to control the flow.
• Jet Needles: It is a small nozzle with multiple holes. These holes spray a mist of air and fuel mixture into the combustion chamber, where it is used as energy to run your two-wheeler.
In conclusion, the carburettor is a vital component of your motorcycle's engine, responsible for delivering the correct fuel-air mixture for optimal performance. Understanding how a carburettor works and its importance in maintaining your motorcycle's health can help you ensure a smooth and enjoyable riding experience.
All this being said, since the mid-90s to the early 2000s, there has been a decisive shift - carburettors are slowly being replaced by fuel injection systems which are better calibrated to maintain the right air-fuel mixture, especially at high altitudes.
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